BackgroundHealthcare-associated bloodstream infections are related to both increased antibiotic use and risk of adverse outcomes. An in-depth understanding of their epidemiology is essential to reduce occurrence and to improve outcomes by targeted prevention strategies. The objectives of the study were to determine the epidemiology, source and concordance of healthcare-associated bloodstream infections with clinical site isolates.MethodsWe conducted a descriptive cross-sectional study in critically ill adults admitted to a tertiary semi-closed intensive care unit in England to determine the epidemiology, source and concordance of healthcare-associated bloodstream infections with clinical site isolates. All nosocomial positive blood cultures over a 4-year study period were identified. Pathogens detected and concordances with clinical site are reported as proportions.ResultsContaminant pathogens accounted for half of the isolates. The most common non-contaminant pathogens cultured were Pseudomonas spp. (8.0%), Enterococcus spp. (7.3%) and Escherichia coli (5.6%). Central venous catheter-linked bloodstream infections represent only 6.0% of the positive blood cultures. Excluding contaminants and central venous line infections, in only 39.5% of the bloodstream infections could a concordant clinical site source be identified, the respiratory and urinary tracts being the most common.ConclusionsClinical practice should focus on a) improving blood culture techniques to reduce detection of contaminant pathogens and b) ensuring paired clinical site cultures are performed alongside all blood cultures to better understand the epidemiology and potential implications of primary and secondary discordant health-care associated bloodstream infections.

Key content There are several obstetric surveillance systems currently used within the National Health Service (NHS). These systems employ a variety of techniques to monitor a range of important health conditions and medical services. Uses of surveillance data include monitoring disease, clinical audit, research and resource planning. A surveillance system must be designed appropriately if it is to achieve its desired purpose and remain a justifiable use of public funds. Learning objectives To be able to identify the different surveillance system types currently employed within obstetrics and their appropriate uses. To understand the advantages and limitations of surveillance system data in obstetrics. To appreciate the importance of appropriate surveillance system design in generating useful data. Ethical issues Surveillance systems contain large volumes of personal data. Relevant legal permissions are required to collect, store and permit access to such data that is often collected without explicit consent.